"Facebook stock up slightly in first day of trading after raking in $16 billion in IPO"

NEW YORK (AP) -- Facebook is trading up 8 percent Friday, as investors seek to put a dollar value on the company that turned online social networking into a global cultural phenomenon.

Earlier, the company's 28-year-old CEO, Mark Zuckerberg, smiled as he rang the opening bell from Facebook's headquarters in Menlo Park, Calif. Surrounded by cheering Facebook employees and wearing his signature hoodie, the 28-year-old pushed the button that signals the opening of the stock market in New York. The morning's events followed an all-night "hackathon" at the company, where engineers stayed up coding software and conjuring up new ideas for Facebook and its 900 million users.

On Thursday, Facebook and the investment bankers arranging the IPO settled on a price of $38 per share. The company and its early investors raised $16 billion in the offering, which valued Facebook at $104 billion. That makes Facebook the most valuable U.S. company to ever go public.

Now, the stock market will assign a dollar value to Facebook that will rise and fall with investor whims. It will be subject to broad economic forces and held accountable for profit it earns —or loses— from one quarter to the next.

But Facebook is one a rare companies whose IPO transcends Wall Street's money lust. It is a cultural touchstone for the way technology reshapes our lives. Since its start as a scrappy network for college students, Facebook has come to define social networking by getting people around the world to share everything from photos of their pets to their deepest thoughts.